What Causes Sore On Penis Foreskin?

my penis is sore on the foreskin i havnt had sex to catch anything i can not get the foreskin back over the head of my penis the foreskin is hanging over the head like a small elephants trunk it is itchy when i try to pull back the skin it bleebs a little iam 54 on warfrin as well its bit embarrasin to ask anyone